This Demonstration shows the behavior of a positively charged particle placed in a system of four uniformly charged wires parallel to the axis. The positions of the wires are symmetrical about the origin in the plane. The magnitude of linear charge density is the same on all the wires, but their signs are negative for the two wires with negative and positive for the wires with positive .
The 3D field window shows the vector field generated by the four wires, the electric potential for every value and the plane (or plane) in which the charge is placed. The distance and controls determine the electric field, while the opacity control optimizes the visualization of the system.
The 2D potential versus distance plot shows the motion of a positively charged particle placed in a given position with a chosen velocity, selected using the sliders "initial velocity" and "initial position". The motion of the particle can be observed by running the animation with the time control. The velocity vector is shown as a red arrow.